The ByMor guide
Lab-grown diamonds: shapes, settings and metals.
Everything worth knowing before you design a piece, in plain English. Read it start to finish, or jump to what you need.
What is a lab-grown diamond?
A lab-grown diamond is a real diamond: pure carbon in the same crystal structure as a mined diamond, with the same hardness, brilliance and fire. The only difference is where it formed. Instead of growing deep underground over millions of years, it's grown in weeks using one of two processes, CVD or HPHT.
Lab-grown diamonds are graded the same way as mined ones, by independent labs such as IGI and GIA, and come with a grading report that lists the shape, carat weight, color and clarity. A standard diamond tester reads them as diamond.
The 4Cs
Every grading report describes a diamond with these four measures.
- Cut
- How well the diamond is proportioned and polished. It drives sparkle more than any other C.
- Color
- Graded D (colorless) to Z. D to F look icy white; G to H look white to most eyes.
- Clarity
- How free the stone is of tiny inclusions, from FL (flawless) down to I. VS stones look clean to the eye.
- Carat
- Weight, not size. One carat is 0.2 grams. Shape changes how big a carat looks.
The 10 diamond shapes
Approximate face-up size shown for a 1 carat stone.
Round
1 ct ≈ 6.5 × 6.5 mm
The most brilliant cut and the classic engagement choice. Maximum sparkle from every angle.
Oval
1 ct ≈ 7.7 × 5.7 mm
Brilliant sparkle in an elongated outline that can make the finger look longer and the stone look bigger.
Emerald
1 ct ≈ 7.0 × 5.0 mm
A step cut with long, clean facets and a “hall of mirrors” look. Elegant, and it shows clarity clearly.
Pear
1 ct ≈ 8.5 × 5.5 mm
A teardrop that blends a round and a marquise. Usually worn with the point toward the fingertip.
Cushion
1 ct ≈ 6.0 × 5.6 mm
A square or rectangle with softly rounded corners and a romantic, pillowy look.
Radiant
1 ct ≈ 6.6 × 5.4 mm
A rectangle with trimmed corners and brilliant faceting, so it has the fire of a round in a modern outline.
Princess
1 ct ≈ 5.5 × 5.5 mm
A square brilliant with crisp corners. Prongs at each corner keep the points protected.
Marquise
1 ct ≈ 10.0 × 5.0 mm
A long, boat-shaped cut with pointed ends. One of the shapes that looks largest for its carat weight.
Asscher
1 ct ≈ 5.5 × 5.5 mm
A square step cut with cropped corners and a vintage, windmill-like pattern.
Heart
1 ct ≈ 6.0 × 6.6 mm
A romantic brilliant cut. The outline reads most clearly at larger sizes.
Ring settings
The setting is how the center stone is held, and it shapes the whole look.
Solitaire
A single center stone held by prongs. Timeless, and it lets the diamond take all the attention.
Hidden halo
A ring of small diamonds tucked under the center stone, visible from the side. Subtle extra sparkle.
Halo
A frame of small diamonds around the center stone. It makes the center look larger and adds a lot of shine.
Three-stone
A center stone flanked by two side stones, often said to stand for past, present and future.
Bezel
A smooth metal rim wraps the stone's edge. Modern, very secure, and great for active hands.
Gold vs platinum
Yellow gold
Warm and classic. Flatters warmer skin tones and vintage designs.
White gold
A bright, modern white that makes diamonds look icy. Usually rhodium plated.
Rose gold
Gold alloyed with copper for a soft blush tone. Romantic and on trend.
Platinum
Naturally white, dense and durable. Heavier and more premium than gold.
| Karat | Gold content | Good to know |
|---|---|---|
| 10k | 41.7% gold | Most durable and most affordable. |
| 14k | 58.3% gold | The most popular balance of color, strength and price. |
| 18k | 75% gold | The richest color, slightly softer. |
Quick answers
How big is a 1 carat diamond?
A 1 carat round is about 6.5 mm across. A 1 carat oval is about 7.7 × 5.7 mm and a 1 carat marquise about 10 × 5 mm, which is why elongated shapes look bigger for the same weight.
Which diamond shape looks the biggest?
Elongated shapes such as marquise, oval and pear spread their weight over a longer outline, so they look larger than a round of the same carat weight.
What's the difference between a halo and a hidden halo?
A halo is a visible frame of small diamonds around the center stone. A hidden halo sits underneath the center stone and is mostly seen from the side.
Which metal is most durable for everyday wear?
Platinum is the densest and most durable. Among golds, 10k and 14k are harder than 18k because they contain more strengthening alloy.
Ready to design yours?
Pick a shape, setting and metal, and watch it come to life.